To uncover their nakedness — I think Mr. Free has made it highly probable, that this phrase does not mean marriage, but fornication, throughout this chapter. So it unquestionably means in the twentieth chapter.
Related Commentaries of Leviticus 18:6
Leviticus 18:6
6 None of you shall approach to any that is neara of kin to him, to uncover their nakedness: I am the LORD.